Classification of colour mutations

discussion with Steiner and Martin

There was a discussion between Steiner and Rensch, in 1932, about the question of both the albino and the lutino can be seen as examples of albinism. This discussion turned out to be a topical subject. I discovered that the same discussion took place between Martin and Buckley in 2002, seventy yeurs later. In these discussions a lot of interesting questions, related to classification and naming of mutations came up. This was for me the occasion to write this page.

Classification

A classification brings order in a poorly arranged amount of facts. The aim is to create a crearly arranged overview. An example is the explosive growth of new colour varieties and new names for mutations in different bird species. The advertisement pages in birdmagazins contain a lot of special offers of bird mutations. The outsider, who is visiting a bird market is overwhelmed by thcolour and names. Orientation is difficult. A good classification and a just namegiving can be a tremendous help.

After 1960 a wave of new colours came into being in parrot species. This development was demonstrated before in canary and budgerigar species. If a fancier wants to develop a good strain a careful choise in needed. The first problem is lacking a good survey of mutations. The second problem is the namegiving of mutations. The internationalisation of hobby of breeding parrots mutations causes a third problem. The colourvarieties are named in the country of regio where they are developed. They become a local name. Using for alle variieties an English name can give problems, because of exclusion of breeders who don't speak English. They are used to local names.

A classification is made up of categories and subcategories. The subject of classification and all categories have to be defined as good as possible.Together they create a simplyfied reproduction of reality. The first question about a classification of bird colour mutations is how the subject is marked out. Most people are careless in using the term mutation. It has to be clear what the subject of classification is.

Distinctive characteristics of a classification system

Accentuation and reduction. To reach the goal of a clear cut classification some aspects of reality are given accent, other aspects of reality are neglected, depending the subject of classification. When the subject is colour change of plumage and eyes the format of varieties is neglected. Not because this aspect is not important but because of the clarity of the classification.

Requirements of a classification system

The subject has to be defined properly. The divisement of the subject in categories has to be well orgunuanised. Every categorie has to be defined also. Overlap between categories has to be avoided. When facts can be categorised in more than one category the classification is unusable. Namegiving of categories is an important matter. The names of categories and sub categories are developed by analising the subject matter. Clear namegiving is an important requirement.

Classifying the lutino and the albino

Problem to solve: One of the problems in the discussion between Steiner and Rensch was the classification of the lutino and the albino variety. The question was: Is the lutino a form of albinisme, just as the albino.

Albinism: The term albinism is in use since more than hundred years. An albino is a man with a total lack of melanin. The white hair, eyebrows and beard, the red eyes is a striking phenomenon. We all know the albino cavia and rabbit with red eyes. The red colour is caused by the colour of blood behind retina who is missing the eumelanin and is translucent.

Albinism in birds: Besides mammals there are albino birds too. Brown birds have only melanin pigments. A total loss of melanin we see in the albino turdus merula. Many coloured birds have melanin and lipochrome pigment. Lipo (Greek) = fat. Chromos (Latin ) = colour. Lipochrome pigmets are named fatcolor pigments becaus fat molecules are transporting the colour pigments. Other names for lipochrome pigments are carotenoid or psittacine pigments. In some bird species who have both melanin and yellow psittacine pigment total loss of the melanin gives way to the lutino colour variety. We see the lutino Spendid, Bourke, Redrump, and in many other species.

Discussion between Steiner and Rensch

Dr. Hans Steiner discussed with Rensch in his book about the colour varieties of the budgerigar (1932). Rensch had the opinion that the lutino variety is not a form of albinism. He developed a new category. The lutino comes into being when there is a division between two pigments. The melanin is disappearing totally, but the yellow pigment stays. He named this category: schizo-chroism. Schizo (Greek) = deviding. Deviding of two pigments. This we see in the lutino budgerigar.The opposite is possible also. The yellow pigment is disappearing totally, the melanin stays. This we see in the blue budgerigar. According to Rensch this variety we can classify in the same category.

Steiner was busy with the development of an own classification system, for brown and multicoloured birds as well. He devided mutations in three categories. Melanin (M), lipochrome (L) and change of the feather structur (S). Steiner had a good reason to disagree with Rensch. The melanin mutation that causes a total loss of melanin pigment is the same in the albino variety of brown birds and the lutino variety in multicoloured birds who possess yellow pigment. Both are examples of albinism.The name albino should be reserved for the mutation in brown birds. These birds have melanin pigments only. A white budgerigar with red eyes is a hybrid, a crossing between a lutino and a blue colourvariety.

Also when we judge the category schizo-chroism based upon the requirements of a good classification system, schizo-chroism is not a correct category. The blue budgerigar is due to a mutation of the psittacine pigments, the lutino budgerigar is due to the mutation of a melanin pigment. Both don't belong in the same category. When it is possible to classify the same pigment distortion in two categories it means that the categories are not correct defined. The fault is an overlap between to diffent categories. The category: schizo-chroism has to be reject on this reason also.

Discussion between Martin and Buckley

I was surprised to read the same discussion about lutino and albinisme in the recent published book of Dr. Terry Martin (2002). He was in discussion with Paul A. Buckley. In his article about genetics and pigmentation of birds Buckley used an other definition of albinism as usual. (page 29). Total albinism is defined as the total loss of melanin pigments. Buckley describes albinism as the abnormal total loss of all pigments. This results in a all-white bird with red eyes, with light beak, legs and nails. Peculiar is the broadening of the definition. Not only the melanin pigments but also the carotenoid pigment are lost. his condition can be produced by genes at several different loci. Probably he was altering the definition of albinism because he wanted to categorize all albino varieties in different species, the brown- and the multicoloured birds and bring them in the same category together

But he created a problem. A lutino budgerigar did not loose the yellow pigment. So he does not fit is his broadend definition. Buckley used the same category of Rensch: schizo-chroism to categorise the lutino. He refined this category a bit. He named this category: melanin-carotenoid chroism.

Martin does not agree with Buckley. The lutino cannot be categories as melano-carotenoid schizo-chroism. He writes: Quote: The lutino is the equivalent of the mammalian albino" (pg 220) . We have to count for the fact that Martin used the names albino and lutino as mutation factors. His point of vieuw we have to read as: what the albino is for mammals is the lutino for parrots.

Differences between Martin and Steiner

Martin is using the same argument as Steiner did. In the lutino and the albino the same total loss of melanin occurs. There are big differences between Martin and Steiner in the consequences they draw from this conclusion Steiner used the discussion with Rensch to develop further his classification system He use the discussion of schizo-chroism to make a new category that could be used for the dividing of two kinds of melanin, the eumelanin and the phaeomelanin. Het named this schizo-melanism. He thought of a new category for mutations that are deviding two lipochrome pigments, the yellow and red pigment. Some birds have a mixture of these pigments. If one of the two is falling out totally, he named this schizo-lipo-chromatism. By this new categories he avoided overlapping of categories. The category schizo-melanism counts for classification of the phaeo variety and the isabel variety. The category schizo-lipo-chromatism is useful for parrot mutations.

The point of vieuw of Martin is that all categories, that are related to albinism, as total albinism, incomplete albinism and partial albinisme are in fact useless for his goal categorising of parrot mutations. They are :Quote: "artificial and flawed" (pg.220) In fact all these categories need modification. With this judgement he is diametrically opposed Steiner.

Martin exchanged the term albinism for the term lutino. This has substantial consequences. Lutino is a colour variety used for birds who have melanin and yellow pigments also. The subject of the classification by Martin is the mutations in parrots. This means that birds without yellow pigment can not be classified in his system. That is a pity. One of the important goals of categorising mutation factor is to find out the relation of mutations in several different bird species. The terms lutino and albinism are not equal and not exchangble. Lutino is the name of a colour variety, used by Martin as a name of a mutation factor. Albinism is a class of colour varieties or mutation factors. This means that the term lutino not can be used as a category of mutations. It is one of the factors, not a a category.

Martin avoid the term albinisme and albino. Abinism is replaced. Albino is a combination of factors. The white budgerigar with red eyes is called blue lutino, a combination of two different mutation factors: lutino and blue.

Steiner developed a classification for all bird species. His oriëntation was the function change of pigment production and atering the feather strcuture. The accent is not the colourvariety or the mutation factor but the altered function, caused by mutation factors and results in changes in plumage and eye colour.This is the reason that the classification can be used for categorisation of mutation factors and colourvarieties as well. Albinism and the categories related to albinisme is an important part of his category system. Albinism is the main category of all melanin distortions.

Mutation factors or colour varieties

In the discussion between Martin with Buckley turns out that both of them have a different oriention on the subject of classification. Martin writes: Quote: "The only systematic way to name mutations logically is to use genetics and gene action, irrespective of the physical apearance of the bird" (pg.24) This point of vieuw can be derived from the critic he has in using the name albino. Quote:" No single gene known can prevent production of both grey family pigments and yellow familly pigments" (pg 51). Quote:"You need the Blue gene to remove the yellow family pigments and the lutino gene to remove the grey family pigments. Together they create an albino." (pg 51) Martin accentuates the inventarisation of mutation factors. Martin creates a reduction of the subject of classification. The possible consequence is that the differences in colourvarieties used by the same mutation factor are neglected.

Buckley has a very different orientation. He describes in his article abnormalities in pigmentation. He neglect the altering of the changes of the feather structure. He is descripting the abnormalities. Buckley is oriented on colour varieties. This counts for the broadening of the definition of albinism also. Here he writes: Quote: "An albino is lacking the alleles of all normally found pigments" (pg. 29). He is neglecting the mutation factors.

Conclusion: Both Martin and Buckley have an other orietation on the subject of classification.Martin accentuated the mutation factors. Buckley accentuated the colour varieties. Buckley neglects the mutation factors. Martin neglects the colour varieties. This does not mean that I don't have admiration for the very complete and comprehensive inventory of parrot mutations. The judgement of every mutation is really a very laborious and painstaking work. My critical review concerns two important matters: neglecting of differences in mutations due to the different genetical make up of bird species and the use of colour names for mutation factors.

Relation between mutation factors and colour varieties

The relation between mutation factor and colour variety is unequal. An mutation factor is a gene that is altered by mutation. A mutation factor is part of the genetical make up, the sum of all hereditary factors of the bird species or varieties of this species. The mutation factor is a part of the genotype. A colour variety is the changed appearance of the bird. The phenotype. A mutation factor is the cause, a variety is the result of change in coloring elements.

The relation between colour variety and mutation factor is indicated by the following rule: The same mutation factor can result in different colour varieties. This is perfectly demonstrated by the total loss of melanin. In brown birds the result is an albino. In green birds the result is a lutino. The reason is clear. The coloring elements of brown birds are restricted to melanin pigments. The coloring elements of green birds are melanin, psittacine and structural elements. The mutation factor is the same. The colour variety depends on the mutation factor and the other genetic qualities of the species. The influence of the mutation factor is always determined by the other genetic factors.

Buckley neglected the genetic differences between birds. This is demonstrated by the new definition of albinism. He does not count for the specific relation between mutation factor and colour variety. His orientation is one-sided.

Martin neglect determined the differences in appearance between bird species and colour varieties. He does not count for the specific relation of mutation factor and variety. His meaning is that all varieties cause by the same mutation factor should have the same name. His orientation is one-sided. This is resulting in neglect of the genetic differences of different bird species that are visible in the differences in colour varieties.

This is proven in different examples.

Blue is a colour variety. Martin is using this colour names for a mutation factor. The Cockatiel does not have structural colours because of the lack of barbs with a bluestructure. A blue colour variety is impossible. The total loss of psittacine pigment means that the yellow pigment in the front and and the red pigment in the cheek is gone. The result is a grey bird with a white head. This is called blue mutation. The genetical make-up of the cockatiel is different from a green parrot like the budgerigar. Differences are neglected.

The rose Galah has red pigment. No yellow pigment. The total loss of melanin is in all species named lutino. In the Galah also. But the genetic factors in the Galah are playing a big role in the colour of the Galah variety. Rubino should be the perfect name. The aspect of the different genetical make-up of species is neglected. The Galah does not have yellow pigment. The genetical make up of the green parrot is the model in naming the mutation factors. Yellow pigment is accentuated. Red pigment is reduced. When the psittacine pigment should be lost totally also, the combination is named blue lutino, a contradiction in terminus. Nothing refers to the Galah.

Name giving of colour varieties and mutation factors

There are several reasons to give colour varieties and mutation factor different names.

1. Colour variety and mutation factor are two fully different aspects of the same subject of classification. A classification should cover both aspects. By one-sided orientation on this subject a undesirable reduction takes place.

2. The relation between colour variety and mutation factor shows that there is no one to one correspondence between both of them. Therefore both cannot have the same name.

3. The causes of colour change cannot indicate with a colour name. The causes are found in the distortion of pigment production and change of the feather structure. The name of a mutation factor should give a explanation. The remark that a blue variety is caused by a blue factor found on a blue locus explains nothing. The name of a colour variety should refer to the difference between the wildtype and the other colour varieties in this species.

4. Colour names are not suited as names of classification categories.

5. A good classification can give insight in the similarities in mutations in different bird species and can show the relationships between colour varieties and mutation factors.

6. Using colour names for mutation factors gives confusion in breeders because several colornames are used for many years for colour varieties. Colour names give false expectations in fanciers who start with breeding mutations and did not know all the ins and outs of the background knowledge. The use of colour names can give communication problems between scientists and breeders.

Summary: To develop a classification both aspects of the same issue should be honoured. Both can placed in the same classification. Both should get different names. The names of colour varieties should refer to the appearance. That part of the appearance that differs from the wildtype and the known varieties of the species. The names should be descriptive names. The names of mutation factors should refer to the changes or distortions of the pigment formation and the feather structure. The names of mutation factors are taken from the scientific disciplines what are involved. This are most English names. In this way international communication is not a problem. Local names of colour varieties are colour names. This names are easy to translate. The communication between researchers and breeders gives no problem when a double name giving is in use.

Literature:

Het kweken van kanaries, F.H.M.Kop, 1986
Genetics for budgerigar breeders, T.G.Taylor and C.Warner, 1961
Handleiding voor de grasparkieten kweker, W.Beckmann, 1966
Neophema’s en hun kleurmutaties, H.P.M. Zoomer, 1987
A guide to colour mutations and genetics in parrots, T.Martin, 2002
Genetics, art. P.A. Buckley in Diseases of cages and aviary birds, M.L.Petrak, editor,1969
Vererbungsstudien am Wellensittich, H.Steiner, 1932

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Copyright 2005, Bob Fregeres

E-mail: fregeres@bourkes-parakeet.nl